Ileal pouch dialysate is cytotoxic to epithelial cell lines, but not to CaCo-2 monolayers.
OBJECTIVE
All patients with ileal pouch-anal anastomosis (IPAA) have some degree of villous atrophy, mucin changes and chronic inflammation. The mechanism underlying these changes is unknown. This study investigates the hypothesis that luminal factor(s) may affect epithelial cells in in-vitro studies.


METHODS
IPAA dialysate from eight patients with prior ulcerative colitis was assessed.


METHODS
The effect of the dialysate on epithelial cell (i-407, HT-29 and CaCo-2) proliferation (3H-thymidine incorporation) and cytotoxicity (51-chromium release) was determined. Bile acid(s) at concentrations measured in IPAA dialysate were assessed in isolation and in combination for cytotoxicity against CaCo-2 cells. The effect of dialysate and bile acids on immature and mature CaCo-2 monolayer cytotoxicity, transepithelial electrical resistance (TEER) and histology was investigated.


RESULTS
IPAA dialysate is antiproliferative and cytotoxic to the cell lines. At concentrations present in dialysate chenodeoxycholic acid and deoxycholic acid were cytotoxic to CaCo-2 cells. IPAA dialysate was not cytotoxic to mature CaCo-2 cell monolayers. TEER was maintained across monolayers with dialysate but not with control Rheomacrodex (P = 0.02). Bile acids at concentrations present in dialysate were cytotoxic to monolayers.


CONCLUSIONS
Ileal pouch dialysate is cytotoxic to epithelial cells due (in part) to bile acids. Bile acids in isolation are cytotoxic to both CaCo-2 cells and monolayers. Despite the presence of bile acid the dialysate is not cytotoxic to CaCo-2 monolayers and preserves epithelial resistance and histological structure.
Merrett
M N
MN
Gastroenterology Unit, Radcliffe Infirmary, Oxford, UK.
Owen
R W
RW
Jewell
D P
DP
D001647:Bile Acids and Salts / Q000032:analysis / Q000494:pharmacology; D018938:Caco-2 Cells; D002455:Cell Division / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D015314:Dialysis Solutions / Q000737:chemistry / Q000494:pharmacology*; D004553:Electric Conductivity; D004848:Epithelium / Q000187:drug effects; D006801:Humans; D016737:Proctocolectomy, Restorative; D013997:Time Factors; D014407:Tumor Cells, Cultured
D001647:Bile Acids and Salts; D015314:Dialysis Solutions